青藏高原东北缘不同利用率高寒草甸植被构成及种间关联  

Vegetation composition and interspecific associations of alpine meadow under different utilization rates on the northeast Qinghai-Tibet Plateau

作　　者：宣文婷 赵一军 李艺妆 刘金银 王先之[1] 于应文[1] XUAN Wenting;ZHAO Yijun;LI Yizhuang;LIU Jinyin;WANG Xianzhi;YU Yingwen(State Key Laboratory of Grassland Agro-ecosysterms/College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,Gansu,China)

机构地区：[1]兰州大学草地农业生态系统国家重点实验室/兰州大学草地农业科技学院,甘肃兰州730020

出　　处：《草业科学》2022年第4期625-633,共9页Pratacultural Science

基　　金：国家自然科学基金(72033009);国家牧草产业技术体系CARS-34。

摘　　要：植被群落结构和种间关系是草地稳定性管理及群落演替主要评价指标。不同利用率下高寒草甸植被构成和种间关系的研究,对于该类草地管理和稳定性维持机制揭示具有重要意义。本研究以青藏高原东北缘高寒草甸为对象,通过对全年平均草地利用率60%~70%(中度,MG)、80%~90%(重度,HG)和> 90%(极度,EG)下草地植被构成、种间关系及群落稳定性进行分析,探究较适宜的草地利用率。结果表明:1) MG草地以禾草[垂穗披碱草(Elymus nutans)、西北针茅(Stipa sareptana)和冷地早熟禾(Poa crymophila)]为优势种,HG草地以垂穗披碱草、矮嵩草(Kobresia humilis)、西北针茅为优势种,EG草地以矮嵩草为优势种。2)随草地利用率增加,群落植物物种数减少,β多样性指数、Shannon-Wiener指数和Simpson优势度指数呈减小趋势,EG草地最低;莎草(Cyperus rotundus)地上生物量比例呈增加趋势,禾草地上生物量比例呈降低趋势。3) MG和HG草地较EG草地植物种间联结性紧密,群落稳定性较强,EG草地呈现一定程度退化。研究结果表明,轮牧制度下的中度草地利用率有利于当地高寒草甸群落稳定性维持。The vegetation community structure and interspecific association are the main evaluation indices of grassland stability and community succession.It is important to study the vegetation composition and interspecific association under different utilization rates for grassland management and revealing the mechanism of stability maintenance in alpine meadow.This study analyzed vegetation composition,inter-species relationship and community stability under the annual average grassland utilization rate of 60%~70%(moderate utilization grassland,MG),80%~90%(heavy utilization grassland,HG)and > 90%(extreme utilization grassland,EG) in the northeastern Qinghai-Tibet Plateau.It aimed to explore the relative suitable grassland utilization rate in the northeastern Qinghai-Tibet Plateau.The results showed that 1) MG grassland dominated by grass(Elymus nutans,Stipa krylovii and Poa crymophila) and HG grassland dominated by Elymus nutans,Kobresia humilis and Stipa krylovii,while the EG grassland dominated by Kobresia humilis.2) With the increasing of utilization rate,plant species richness decreased,and the β diversity index,Shannon-Wiener diversity index and Simpson dominance index showed a declining trend,reaching the lowest in EG grassland;the aboveground biomass proportion of sedge increased,while the aboveground biomass proportion of grass decreased.3) Compared to EG grassland,MG and HG grasslands had a closer interspecific association and stronger community stability,and EG grassland showed a trend of degradation.The study concluded that the moderate utilization rate under the rotational grazing pattern was beneficial to maintain the vegetation community stability in alpine meadow.

关 键 词：高寒草甸 草地利用率 物种多样性 种间关联 群落稳定性 

分 类 号：S812[农业科学—草业科学]